Unable to install breakpoint due to missing line number attributes

I was happily coding along, and didn't change anything in the Eclipse configuration, just a few lines of code since the last time, and hit F11 to start debugging. I had set a breakpoint to see the output of the BCrypt hashing implementation I put in.

An error dialog popped up with the message:

Unable to install breakpoint in 
com.lisedex.volinfoman.server.admin.BuildDB$$FastClassByGuice$$22710124
due to missing line number attributes.  Modify compiler
options to generate line number attributes.

Reason:
Absent Line Number Information

Crap. Well, I didn't change anything, but I thought maybe I hit some key combination that turned off line numbers? I checked Window -> Preferences -> Java -> Compiler, but sure enough, the line number checkbox was ticked. So I unticked it, applied the settings, came back and re-ticked it, but no luck. Did some quick searches, and people recommended checking that option, or adding -g to the compiler options, but that doesn't really seem to be an option here.

Added a bunch of logging to look at what I wanted to see, and went ahead and ran the program anyways, OKing through the dialog.

It stopped at my breakpoint.

I tried this in several other places in my code, and they all work. I still get the error, but it doesn't appear that the problem actually exists.

So if you see this error, my suggestion is, before wasting a bunch of time trying to fix it, see if it's actually true. You may just be able to check the box for it to not notify you, and go on with your life.